Currently in fractal_noise functions, each subsequent octave doubles the frequency and reduces the amplitude by half.
This patch introduces Roughness input to Noise and Wave nodes. This multiplier determines how quickly the amplitudes of the subsequent octaves decrease.
- Value of 0.5 will be the default, generating identical noise we had before.
- Values above 0.5 will increase influence of each octave resulting in more "rough" noise, most interesting pattern changes happen there.
- Values below 0.5 will result in more "smooth" noise.
Changes in code are simple but feature itself is quite significant, it will allow creating vastly different looking noises very easily.
This property is sometimes called "Persistence" but most CG software name it "Roughness". I leave naming decision to reviewers.